1. Technical Field
The present invention relates to a semiconductor device, a display device, a display apparatus, and a system.
2. Description of the Related Art
A LCD (Liquid Crystal Display), an OELD (Organic ElectroLuminescence Display), or a FPD (Flat Panel Display) such as electronic paper is driven by a drive circuit that includes TFTs (Thin Film Transistors) where amorphous silicon or polycrystalline silicon is used as semiconductor layers.
In development of FPDs, technology to manufacture and apply TFTs including field-effect transistors that use oxide semiconductor films with high carrier mobility and small interelement variations at channel-forming regions of semiconductor layers to electronic devices, optical devices, and so forth, has been attracting attention. For example, a field-effect transistor where zinc oxide (ZnO), In2O3, In—Ga—Zn—O, or the like is used as an oxide semiconductor film has been proposed.
As a field-effect transistor, for example, a field-effect transistor of top-gate and top-contact type which has such a structure that it is easy to reduce the contact resistance of the semiconductor layer with respect to the source and drain electrodes made of metal films (for example, see Japanese Patent No. 5118811) is used. In the field-effect transistor, the semiconductor layer is inserted between the base, and the gate insulating layer and the gate electrode advantageously from the viewpoint of moisture and oxygen in the outside being able to be blocked.